Flotation of minerals



UNITED STATES PATENT om c's.

CLEMENT L. PERKINS, 0F PITTSBURGH PENNSYLVANIA, ASSIGNOR TO METALSRECOVERY COMPANY, OF NEW YORK, N. Y., A CORPORATION OF MAINE.

-FLOTA'1ION OF MINERALS.

Specification of Letters Patent.

Patented Jan. 4, 1921.

1l',36d,306. No Drawing. Application filed July 21, 1919. Serial No.312,249.

T 0 all whom it may concern Be it known that I, CLEM NT L, PERKINS, acitizen of the United States, residing at Pittsburgh, in the county ofAllegheny, State of Pennsylvania, have invented certain new and usefulImprovements in Flotation of Minerals; and I do hereby declare thefollowing to be a full, clear, and, exact description of the invention,such as will enable others skilled in the art to which it ap-.

pertains to make and use the same.

This invention relates to the concentration of minerals, such as sulfidores and the like,

by flotation, and is based upon the discovery I that improved resultscan be obtained by carrying out the flotation operation with theaddition to the ore or mineral pulp of hydrazins, such asphenyl-hydrazin, etc.

Among the hydrazins and their derivatives, including thehydrazo-compounds or diaryl-hydrazins, which can thus be used, may bementioned the following :phenylhydrazin, either in the form of the freebase or in the form of its salts, such as the hydrochlorid or sulfate;naphthylhydrazin, as the free base or in the form of its salts; paratolyl hydrazin; acetic phenyl hydrazid, CH .CO.NH.NH.C H acetonephenyl-hydrazone (CH C:N.NH.C H tribromphenyl-hydrazin; hydrazo-benzeneor symmetrical di-phenyl-hydrazin C H NHNH. C H etc. The hydrazins ortheir derivatives may be added either in the form of the free base, or'in the form of salts thereof withaCids. In referring to hydrazincompounds, therefore, I intend toinclude the simple and substitutedhydrazins and their derivatives, whether in the form of the free base,or in the form of salts thereof.

The hydrazin compound which I have found of particular value, and whichI therefore recommend, is phenyl-hydrazin (C H NIINIL). In usingphenyl-hydrazin, it may be incorporated with the ore or mineral pulp inany suitable manner, for

example, by introducing it into the tube mill in which the ore is beingground, or by adding it directly in its liquid form to the ore pulp, orby first digestingit with water and adding the resulting product, or bymixing it with an organic liquid mixable therewith.

In general, however, it seems that the hydrazins can be moreadvantageously added to the pulp immediately before flotation, ratherthan to the grinding mill. Liquid compounds, such as phenyl hydrazin,may be added directly; others, 6. 9., in the form of.

solutions in water or in various organic solvents.

Phenyl-hydrazin, as well as the other hydrazin compounds, have a markedaction as collecting gents; that is, agents which cause a very materialincrease in the recovery of mineral when used in connection with a suitable frothing agent. The hydrazins themselves nevertheless havea,considerable frotheither.

has been thoroughly and uniformly distributed throughout the ore ormineral pulp, the, resulting mixture'is subjected to a flotationoperation, as .in an ordinary Ca1low.,

cell, or in apparatus where the air is incorporated in the ore pulp bymechanical agi- L tation.

It is of advantage in many cases to add to the ore pulp a small amountof alkali, not only when the hydrazin compound is used in the form of asalt, but also when the free base is employed. When a salt of thehydrazin is employed, the alkali may act upon I it, to a greater or lessextent, to set free the free base, but the action ,of the alkali appearsto be an action upon the ore pulp, or upon the mineral constituents,rather than or in addition to its action upon the salt of the hydrazinused, although I do not desire to limit myself by any theoreticalexplanation of what the action of the added alkali may be in promotingthe flotation operation.- A similar improvement in the process has beennoted both when alkali has been used with the free base, and when usedwith salts of the hydrazin. The. alkali may be caustic alkali, such assodium hydrate, or an alkaline salt, such as sodium carbonate," or

even lime or calcium oXid or hydrate can be used. Varying amounts of thealkali can be added, but in many cases it 1s desirable to add suflicientto give a distinct alkaline reacalkali, evenwhen the lime was added tothe" ground pulp in theJanney cell, and with tion to the orepulp. duringthe flotation; operation. When' sodium" hydroxid is used .withphenyl-hydrazin it appears possible to use a somewhat reduced amount ofphenylhydrazin. I have also obtained excellent recoveries when lime wasused as the added the consumption of about from onerfifth to calledporphyry ores, such as those-of the *tically no collecting properties.

one-fourth pound of phenyl-hydrazin per ton. The limenot only hasanalkaline reaction, but it may have a beneficial effect in helping tosettle the ore pulp. j 4

The amount'of the hydrazin onliydraz'i'n derivatives added may varysomewhat,- and may be as little as one-fifth or one-fourth pound per tonOff ore; (that is, calculated on the welghtv of the'ore, and not of theore pulp); but larger amounts may, with advantage, be' used,particularly where no added frothing agent orflotation agent is used,and as much as one or one and one-half pounds 'used. i t

Thehydrazins and hydrazin derivatives have proven to be of particularvalue in the flotation'of copper sulfid ores having a silicious' gangueand containing their floatable per ton of ore, or even more, can be orsulfid copper in the .form of a mixture.

of chalcocite and chalcopyrite; thatis, so-

Utah Copper Company. When using phenyl and naphthyl hydrazins, the bestresults appear to be obtained by Ngrinding the ore with water and alkaliadding the hydrazin to the groundpulp'im- -mediately before flotation.The results obtained in this Way were better than those obtained. byadding the hydrazins in the aOH) and then grinding mill.

Where the phenyl-hydrazin or other hydrazin compound or derivatives isused with other flotation agents, it will materially im prove theflotation result by its marked action as a collecting agent. Theflotation agent With which the hydrazin compound is added may,therefore, with advanta be a flotation agent with markedfrothingproperties, for example, pine oil, orother wood distillation oils, or'terpineol, which has marked frothing properties, but prachydrazin isused with a frothing agent, the

valuable collecting properties of the hyh drazin Will thus besupplemented by the frothing properties of the frothingagent.

Where the hydrazin compound is miscible g with the other flotation'agentor agents with it is to be used, the agents may be which first admixedand compounded to form a composite flotation agent, and the compositeagent then added to the ore pulp. .When

the hydrazin is a solid and, not readily solu b'le or miscible with theorepulp, it may be ground in the ball mill, or dissolved in a suitable,organic solvent therefor,

,entinvention,

.drazins and When theamount of an aryl-hydrazin' 0 larlya solvent whichis itselj. readi y miscible ,with the ore pulp, and the resultingsolution then added to the ore pulp. If the hyd'razin is soluble inwater, it maybe added in the form ofan aqueous solution.

' It is a characteristic of the process of the present invention thatthe frothobtained is readily broken up, while arelatively cleanconcentrate and high recovery can, nevertheless, be obtainedp Theconcentrate first articw,

obtained, for example, from'a rougher cell, l

v can, of course, be further .concentrated, and

the grade of the concentrate thereby further improved, by treatment in acleaner cell or cells. i r

The process of the present invention, in

whlch hydrazins are employed, is somewhat 11 related to the process ofmy companion appllcation; Serial No. 312,248 filed of even date herewithin which azo-compounds, diazo compounds,

compounds used in the process of the presecting theresulting mixture toa flotation operation; substantially as described. 2. The method ofeflecting'the con-centra tion of'minerals by flotation, which comj,prises adding to the mineral pulp a small amount ofa hydrazincompound,together with a flotation agent having marked frothing properties, mxture to a flotationoperation; substantially as described. L v

3. The method of effecting the concentration of minerals by flotation,which comprises addingto the mineral pulp a small a h drazin substance,together.

amount of with suflicient a kali to give to the ore pulp a..distinctalkaline reactlon; and subjecting the resulting mixture toa flotationtion; substantially as described.

4. The method of efi'ecting a concentradilfer frpm the azo and diazocompounds by the fact that the two nitrogen operaand the like, are ,em-

-ployed; but the hydrazins and hydrazina single bond and likewise havetion of minerals by flotation, which comprlses adding to the mineralpulp a small amount of a hydrazincompound, and sub- 1'10 and subjectingthe resulting tion oflminerals by flotation, which comprises adding tothe mineralpulp a small the general formula R-NH.NH (where R stands foran aryl radical) and subjecting the resulting mixture to aflotation'operation; substantially as described.

.5. The method of effecting the concer-i .1-

the resulting" mixture to a flotation opera tion; substantially asdesoriloeel.

6. The method; of. effecting the concentration of minerals by.flotation, which coinprieee adding to the mmeralpulp a small amount oila hydrazin compound, in the r a H r i 1 .[OIIII ol a salt theieof witaan aoio, ano subyecting the resultmg mixture to a flotation operation.

7. The method of ellectmg the concentra tion of minerals by flotation,which com- 15 prises adding to the mineral pulp a small 4 l A a 4 e a Ation out minerals by fiotatwn, which eoinamount oi phenyl hydrazm,together with prises adding to the m neral pulp small aiifiment'alkah togive to the ore pulp a amount of phenyl-hytlicazin and aah eoting"distinct alkaline lBitC'iLlOll, ancl suhwctlng the resulting mixture toa flotation operation; substantially as clesei'iloeol 8. lhe method ofeffecting the concenttation of minerals by flotation, which oompriseeadding to the mineral pulp a small amount oat phenyl hydrazin, togetherwith an agent having good trothing qualities, and subjecting theresulting mixture to a flotation operation; scribed,

ln testimony whereof I affix my signature.

CLEMENT L, lFERKlNS,

substantially as ole

